Surface induced dissociation with reflectron time-of-flight mass spectrometry
US5144127A · kind A · utility
Inventors
Key dates
| Filing date | Aug 2, 1991 |
| Grant date | Sep 1, 1992 |
| Priority date | — |
| Expiry date | Aug 2, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/0068
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Surface induce dissociation (SID) in a reflectron tandem time-of-flight mass spectrometer is demonstrated using a movable "in-line" SID surface in the reflectron lens. For collisions under 100 eV, SID spectra are measured with a resolution of .about.65 (FWHM) with dissociation efficiencies of 7-15% obtained for most small organic ions. For larger peptide ions (m/z>1200) formed by laser desorption, efficiencies as high as 30-50% are obtained. Surface collisions of polycyclic aromatic hydrocarbon ions can be made to produce abundant pick-up of large, surface-adsorbed species. Attachment of C.sub.1 H.sub.n -C.sub.6 H.sub.n to naphthalene and phenanthrene ions occurs with collision energies between 40-160 eV. Formation efficiency for these ion-adsorbate attachment reactions can be as high as 0.8%. Surface collisions produce no measureable shift in our flight times nor distortion in peak shapes for these species; this indicates the reaction time on the surface must be less thant 160 ns. Theoretical calculations show that these reactions are direct (<300 fs residence on the surface) and thus proceed by an Eley-Rideal mechanism.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.